get error nil class on search form rails code example

Example 1: rails get source method

class A
  def foo
  end
end

file, line = A.instance_method(:foo).source_location
# or
file, line = A.new.method(:foo).source_location
puts "Method foo is defined in #{file}, line #{line}"
# => "Method foo is defined in temp.rb, line 2"

Example 2: laravel return view in web.php

Route::get("/page", function(){
   return View::make("dir.page");
});